"Many aliens who illegally enter the United States and those who overstay or otherwise violate the terms of their visas present a significant threat to national security and public safety," the order states. "This is particularly so for aliens who engage in criminal conduct in the United States."

Anyone who came to the U.S. illegally -- that is without passing through border inspection committed a criminal misdemeanor and could fall into the priority removal category, legal experts tell ABC News.

While overstaying a visa is not a criminal offense, legal experts say that those who do so could fall under a vague clause in the executive order that undocumented immigrants who "have engaged in fraud or willful misrepresentation in connection with any official matter" are a priority for deportation as well.

"This is scary stuff for America's legacy of immigration, for business and for our hospitality," said Michael Wildes, an immigration attorney who formerly represented Trump Models, the Miss Universe Organization and Melania Trump.

"Lady Liberty is probably closing her eyes right now in New York Harbor."

The executive order is "remarkably broad," said David Martin, a University of Virginia School of Law professor who specializes in immigration, constitutional law and international law.

"This order takes that notion of 'criminal alien' to its farthest reaches," Martin continued.

A professor from Yale Law School, Peter Schuck, also called Trump's executive order "extraordinarily broad" and said that one provision that states "ensure that jurisdictions that fail to comply with applicable Federal law do not receive Federal funds" could be read to mean all federal funding, not just law enforcement assistance going to sanctuary cities such as San Francisco, Austin and New York.

The orders stipulate an increase in the number of border patrol enforcement officers and lay the groundwork for building a wall on the U.S.-Mexico border, a longtime campaign promise of Trump's.

"President Trump's fantasy of sealing the border with a wall is driven by racial and ethnic bias that disgraces America's proud tradition of protecting vulnerable migrants," said Omar Jadwat, the director of the ACLU's Immigrants' Rights Project.

"The DHS deportation force has a track record of racial profiling and excessive force abuses, and expanding it will further erode the rights of millions of people who call our safe border communities home. Locking up asylum seekers who pose no danger or flight risk is unconstitutional and benefits nobody except private prison corporations and politicians looking to score rhetorical points. We will see the Trump administration in court if they go down that road," Jadwat said in a statement.